From cba63c3089fe57bfafff56239a67ac26bfe027a0 Mon Sep 17 00:00:00 2001 From: Bernhard Walle Date: Thu, 18 Oct 2007 23:40:58 -0700 Subject: Extended crashkernel command line This patch adds a extended crashkernel syntax that makes the value of reserved system RAM dependent on the system RAM itself: crashkernel=:[,:,...][@offset] range=start-[end] For example: crashkernel=512M-2G:64M,2G-:128M The motivation comes from distributors that configure their crashkernel command line automatically with some configuration tool (YaST, you know ;)). Of course that tool knows the value of System RAM, but if the user removes RAM, then the system becomes unbootable or at least unusable and error handling is very difficult. This series implements this change for i386, x86_64, ia64, ppc64 and sh. That should be all platforms that support kdump in current mainline. I tested all platforms except sh due to the lack of a sh processor. This patch: This is the generic part of the patch. It adds a parse_crashkernel() function in kernel/kexec.c that is called by the architecture specific code that actually reserves the memory. That function takes the whole command line and looks itself for "crashkernel=" in it. If there are multiple occurrences, then the last one is taken. The advantage is that if you have a bootloader like lilo or elilo which allows you to append a command line parameter but not to remove one (like in GRUB), then you can add another crashkernel value for testing at the boot command line and this one overwrites the command line in the configuration then. Signed-off-by: Bernhard Walle Cc: Andi Kleen Cc: "Luck, Tony" Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Paul Mundt Cc: Vivek Goyal Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kexec.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index ad4b82ce84a..2d9c448d8c5 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -187,6 +187,8 @@ extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; extern size_t vmcoreinfo_size; extern size_t vmcoreinfo_max_size; +int __init parse_crashkernel(char *cmdline, unsigned long long system_ram, + unsigned long long *crash_size, unsigned long long *crash_base); #else /* !CONFIG_KEXEC */ struct pt_regs; -- cgit v1.2.3